Check out this great Website called IceBike.They have tested just about every thing that’s related to winter biking.These guys are up in Alaska so I pretty much trust anything they say. I got the idea to get my Bear Claws to keep my hands toasty from them.They also turned me on to riding with sandals all year round. In extreme temps I could put about 5 layers of socks on with a gortex ski sock as the last one,really works way better than shoes!

Alternative Solution:

Believe it or not in some cases less is more.
wpe1.gif (4446 bytes)There are a number of cyclists, not always in the coldest of climates, but plenty chilly never the less, that swear by SPD Sandals, either from Shimano, or those pictured at right from Lake.
What’s this, you say, are they Daft?   Not at all.  
Sandals adopt quickly to the addition of another layer of socks, Gore-Tex Oversocks, or neoprene booties.  When out in the cold wet, you won’t have wet shoes, as no water accumulates, it all runs off. 
Further, you may not need to change upon arrival at your destination.  All you do is strip off a layer of socks (or two), cinch up the straps, and you can wear them around the office or the house.
Cyclists in rainy Cold-Wet climates like Seattle swear by them.

If theres anything you want to know about winter riding this is the place!!
http://www.icebike.org/Default.htm
Hope this keeps you going all winter!!
Urban Mobility Project